Film-Tech Forum ARCHIVE: DTS Setup Disc Q's

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Posted by Joe Redifer (Member # 3) on 04-27-2009, 10:12 PM:

OK, it has been nearly 10 years since I set up a DTS system. I lost my Empirical Test Disc and have downloaded the DS3 Setup Disc from this site. Will this suffice? All I really want to do is run pink noise for all channels and set them to line level (300mv I believe). I haven't burned the disc yet, but I recall being able to switch tracks (or "reels") with the delay offset on the player. I also remember being able to play "reels" from real movies by booting the setup disc along with a regular movie disc in drive "A".

I have a DTS-6D, by the way. Remind me how to set this up.

Posted by Tony Bandiera Jr (Member # 2365) on 04-28-2009, 01:01 AM:

Hi Joe, the DS3 disc is the correct one to use for setup. IIRC the Empirical Test disc was just that, and was NOT to be used for setup. It was a quick test for system levels by ear and performance of amps and speakers.

See page 17 of the DTS-6D manual here on the site.. (My Adobe reader wouldn't let me copy and paste the text.)

You need to use an SPL meter to set the correct levels in the room. Using the "300mv" output measurement from the DTS-6D is ONLY when you have the DTS Surround EX adapter hooked up, then the DTS adapter is set to output the proper SPL's on each channel, using the meter in the auditorium.

And switching tracks is done with the little black index button.

Posted by Joe Redifer (Member # 3) on 04-28-2009, 01:27 AM:

If I planned to leave this unit in one auditorium, then hooking it up and setting the levels once would be fine. But I want this unit to be plug and play without resetting the levels each time, just the reader offset. Why DTS made their system with adjustable output levels is beyond me. The Dolby Digital DA10 and DA20 didn't need this nonsense.

Posted by Demetris Thoupis (Member # 833) on 04-28-2009, 04:14 AM:

Actually you also need an analyser for Subwoofer level.
Demetris

Posted by Marco Giustini (Member # 4544) on 04-28-2009, 04:34 AM:

What I know is that you just set all the output for 300mV, EX or not. Then you can install the unit where you want, like a DA20. Be sure that your meter is reliable at those frequencies (1000Hz for all channels, 30 for sub), eventually you can check with an oscilloscope.

Marco

Posted by Scott Norwood (Member # 30) on 04-28-2009, 12:31 PM:

Does anyone really still use rollaround racks for digital sound? DTS 6Ds show up pretty regularly for reasonable prices now, so I don't quite see the point, especially if you have multiple types of sound processors which expect different input levels.

Anyway, the setup instructions are in the DTS 6D manual on this site. It's pretty trivial.

Posted by Tony Bandiera Jr (Member # 2365) on 04-28-2009, 12:53 PM:

quote: Marco Giustini
What I know is that you just set all the output for 300mV, EX or not. Then you can install the unit where you want, like a DA20.

Then you were told incorrect information. You use SPL readings, NOT "300mv" as the magic setting for all sizes. As I'd said, according to DTS, the ONLY time a 300mv setting is correct is when using DTS' EX adapter!!

Having said that, like all rules there are exceptions...

In MANY (BUT NOT ALL) cases, it turns out that an output setting around 300mv will result in proper SPL in the auditorium...BUT IF AND ONLY IF the cinema processor's B-Chain levels are set properly. I have seen variations of up to 6dB or more going from one room to another with a portable system. (And almost always I found the B-Chain not set up properly.)

In short, to do it right, use an SPL meter.

A 300mv output level might be ok but don't be surprised to have some variations in level from one auditorium to the other.

I consider the 300mv mark as a good starting point only.

A good test to see if your DTS levels are right is to force an analog fallback and see if the volume changes significantly. Use a fairly loud passage for that test.

Posted by Bruce Hansen (Member # 281) on 04-28-2009, 01:08 PM:

It's been a long time since I downloaded the DS3 file, but somewhere there was a PDF file that told you what is on the disc, and how to get to it. If I remember ccorrectly, some of the stuff you get to by hitting the track change button, other stuff you had to use the delay switches.

Posted by Gordon McLeod (Member # 33) on 04-28-2009, 02:39 PM:

The correct way is use track 2 which is tone and set the unit for 300mv (assuming that is the buss level of the processor)
which by the way is the same method for setting up dubbers and the likes

Posted by Joe Redifer (Member # 3) on 04-28-2009, 03:47 PM:

Thank you Gordon.

Tony, if the levels are off from house to house, then OF COURSE the B-chain levels of the processor are off. I have set the levels of each processor myself. If there was a level problem, I'd rather fix it in the processor instead of on the DTS unit, that way everything gets fixed.

Scott, the only reason I'd ever use DTS is because sometimes we get an Indian print which has no Dolby Digital or severely damaged Dolby Digital and just happens to include the DTS disc with the print. These Indian prints only play 1-3 times maximum and not always in the same auditorium. No need to buy more DTS units.

Posted by Steve Guttag (Member # 268) on 04-28-2009, 05:17 PM:

Sorry Tony...you are most certainly wrong on this one. Using the tones on the disc...300mV in a Dolby cinema processor or any other processor that is designed to accept the Dolby DA10/20 processor is the only correct way. If you use an SPL meter...I can all but guarantee that you won't have a properly balanced system from format to format.

If you get your levels right with the tones, you will have a very precise balance between analog and digital...done it many, many, many times.

The bottom line...don't try to fix B-chain problems with A-chain devices.

Joe, the reason for the adjustment with DTS has to do with when DTS first came out...there was no standard on Aux inputs...and many aux inputs had to be created, somehow. Ultra Stereo, for instance, referenced .775V (0dBu) rather than 300mV (-8.2dBu).

Note, starting with the XD10, DTS now references their output in dB with 0dB equalling 300mV reference...thus most can just install them right out of the box...adjustments are still available to suit other situations.

Steve

Posted by Mike B. Smith (Member # 2829) on 04-28-2009, 06:45 PM:

Thanks Steve well said, Gordon gets a thumbs up too. The most current test disc is the DS 5, however the DS 3 can be used to set levels. On the DTS-6D once the disc starts to play you can push the index switch to fast forward to track 2 which has the 1K tone, it will play for about a minute before going to the next track. For continuous play, set the offset switches to 02 after the disc starts to play, don’t forget to reset switches back to the original calculated settings when done. DTS does recommend setting to 300mV using 1K, the DTS is an A-chain device as Steve stated, most Cinema Processor 6 track inputs are 300mV, so if the B-chain of the processor has been set correctly, the DTS levels should be good, however their
may be some exceptions but rarely. Also to defend Tony’s statements, some manuals have stated using the SPL method, it can be done that way but using the 1K method is much more accurate. Since DTS does recommend this type of calibration we have created a test card that will help speed this process up. You plug the audio out from the DTS to this card, attach your volt meter to the card as well, run the disc adjust to 300mV and you’re done. Two types of these test cards are available; one is the E313-01 the other is E313-00. The difference, one has a rotary switch to select channels, the other you must move your meter probe to each channel. There is a DTS tech notice “TN-E392” which explains it all, and can be found on the DTS web site if your lucky. Also for a limited time, while supplies last, (I have quite a few) contact me with your mailing address and I’ll send you one of these test boards with instructions at no charge.

Posted by Joe Redifer (Member # 3) on 04-28-2009, 07:13 PM:

PM sent!

Posted by Demetris Thoupis (Member # 833) on 04-29-2009, 04:52 AM:

Make that 2 PM

Posted by Tony Bandiera Jr (Member # 2365) on 04-30-2009, 01:38 PM:

quote: Mike B. Smith
Also to defend Tony’s statements, some manuals have stated using the SPL method, it can be done that way but using the 1K method is much more accurate.

Thanks Mike. I made my posts based on the manuals I have on hand as well as the one on this site. So for a while anyways, I was right.

When did the recommended procedure change?

Posted by Marco Giustini (Member # 4544) on 04-30-2009, 03:56 PM:

First time I've read about it was about 2000 I think.

Posted by Mike B. Smith (Member # 2829) on 05-01-2009, 04:00 PM:

The last DTS-6D manual was done in 1999. The first Tech notice (TN-E392)adjusting levels using the 1K method went out in 2001.
Brief history, in the beginning, the procedure to adjust levels on the DTS-6 was to use a SPL meter; I don’t know why this method became standard procedure at that time although it may have been for many reasons, one comes to mind is that in the early digital audio days there was concern about speaker damage and wanted installers to audible adjust the DTS player. Although using the SPL method was not the best way especially with subs, it worked fine and this procedure continued to be recommended into the 6D’s as well. What began the push to change this method was the continuous complaint DTS sounded louder than the optical track. After some investigation we found that a certain pink noise card had a 1.5db error, which was quietly confirmed to us by the maker of that card. Lowering the SPL setting by 1.5db on the DTS corrected the level problem. With this information we finally convinced the decision makers at DTS that the players are an A-chain device and should be adjusted as such, and if the processor level was set up right or wrong the DTS would match that level. So a self playing disc was created that had a 1K tone track, (the DS-2) and soon after that the E313 test board was made for easy access to the outputs for adjustments. Test discs DS-2 through DS-5 all have the 1K tone, difference in later discs they had more test tracks. DTS products after the 6D have a factory default setting of 300mV output but still retained the ability to make individual channel level adjustments.

Posted by Tony Bandiera Jr (Member # 2365) on 05-03-2009, 01:16 AM:

Mike, thanks for the history update, it confirms how I was not quite up to date with the proper level settings and it does indeed make sense to now treat the DTS as an "A" chain device.

Got the card and goodies today as well, thanks. I will also make a mental note to update my install setups, and I'll reset the 6D at UC Irvine. (I had set it up with the old disc and the SPL method.)

Posted by Demetris Thoupis (Member # 833) on 05-04-2009, 05:42 AM:

Mike received the card! Thanks a millionm [Smile]

Posted by Phil Ranucci (Member # 3820) on 05-04-2009, 06:00 PM:

Mine arrived, many thanks!

Posted by Pete Naples (Member # 761) on 05-05-2009, 11:02 AM:

What they ^^ said [beer]

Posted by Richard May (Member # 2627) on 05-05-2009, 11:27 AM:

I guess that why I always had to set DTS levels 2db lower when I set them up. Thanks for the package Mike.